The chief spokesman for the National Republican Senatorial Committee said that a vote for the bill would end up being a political “minus” for Democratic senators likely to face tough re-election battles in 2014 — specifically Mary Landrieu of Louisiana, Mark Begich of Alaska, Kay Hagan of North Carolina and Mark Pryor of Arkansas.

“It’s just another sign that even vulnerable Democrats like Landrieu, Begich, Hagan and Pryor are a more loyal to Chuck Schumer and Barack Obama than they are to middle-class men and women struggling in their home states,” NRSC strategist Brad Dayspring said in a statement.

All four Democrats are expected to vote “yes” on the bill along with the rest of their Democratic colleagues. But at least 14 Republicans are expected to vote the same way, including Florida Sen. Marco Rubio, one of the architects of the legislation.

But in late May the same NRSC that on Thursday criticized the four reform-minded Democrats, released a 90-second web video featuring Rubio touting the benefits of immigration reform.